Raconteur is an acceptance test framework for C#.
Allows writing stories in plain English.
The stories are executed as xUnit tests.
Offers more freedom than other BDD frameworks.
And it's better integrated with Visual Studio.
Because FitNesse has too much friction
Because Cucumber enforces the GWT syntax
Because SpecFlow didn't exploit the host language
Because StoryTeller is pure fiction
That is, while we highly recommend any of those tools
we feel that Raconteur works better in our context.
Furthermore, not even Raconteur will save you from making a mess
if the focus is on the tool instead of on whole team communication and collaboration.